The present invention relates generally to the field of the manufacture of electrical coil windings, and more particularly to a unique cable assembly for use in winding coils having small wires and a large number of winding turns. The predominant current usage of the correction coil cable of the present invention is as the winding wire for correction coils in the superconducting super collider and in similar devices which might be developed in the future.
The varying needs of the electronics industry have produced a very great variety of different electrical coil configurations adapted to specialized purposes and a corresponding variety of methods for producing them. For example, U.S. Pat. No. 4,574,261, issued to Cochran, teaches an unusual coil having metal foil windings separated by an film insulation and further having a unique cooling means. However, the advances in technology which have allowed for development of a superconducting super collider (SSC) have posed a heretofore unknown set of requirements upon those persons engaged in the attempt to wind correction coils therefor.
The magnets in question must be extremely small size in relation to the great quantity of individual and separate windings required and in relation to the field which those windings are required to produce. Furthermore, since these magnets are field trimming coils, they may require individual leads from each winding set. Furthermore, in this application, current must be kept relatively low (in the range of approximately 100 A) in order to reduce helium boil off in the SSC. Additional requirements are that the coils must be stacked on top of each other coaxially so that the total coil length is maximized for the space available, and further so that operating field levels within the coil will be as low as possible to ensure that the correction coil will not quench (drop out of the superconducting condition and return to normal conduction properties). Furthermore, cost analysis has shown that a stacked coil configuration is most cost effective. This combination of requirements necessitates the use of very small wires, which makes the coil winding and coil assembly processes very difficult using known coil winding materials and methods.
Yet another factor which has come into consideration in the development of the present invention is that it has been the accepted wisdom in the field that the random aspect of wire placement which resulted from the best known prior art methods for producing these coils was not a serious problem. However, the inventor has demonstrated that a significant improvement can be had by reducing that randomness as much as possible.
Prior to the advent of the present invention, developmental correction coils for the SSC have been produced using individual wire strands wound using relatively conventional techniques. All of the prior art correction coil windings within the inventor's knowledge have been extremely expensive to produce, given the great care that must be exercised to carefully place the individual wire strands. Furthermore, even given the great effort and expense applied to the task, the resulting correction coils have been less than ideally uniform.
No prior art correction coil winding means, to the inventor's knowledge, has successfully provided a uniformly wrapped coil. Even the most successful correction coil winding materials and methods to date have produced coils having windings with at least some uneven spaces therebetween resulting in poor performance related to poor mechanical array within a winding cross section and, further, have resulted in coils which are very expensive to produce due to the care which must be taken in the production and also due to a high proportion of unacceptable end product.